1. Field of the Invention
The present invention relates to an object recognition apparatus which is used to be mounted on a movable body such as an automobile, an airplane, a ship and a robot, or a non-movable body such as an outdoor monitoring system.
2. Description of the Related Art
As an apparatus mounted on an automobile or the like, for recognizing an object in front thereof, a stereo camera has been known. This stereo camera has a function of observing a target object from different visual directions, and of measuring a distance up to the target object. The technology of the stereo camera is already broadly known in accordance with, for example, Jpn. Pat. Appln. KOKAI Publication No. 5-114099, and the like.
It is difficult in general for the stereo camera to detect an object and detect a distance appropriately in a dark place. Further, when a target object is in a low contrast even in a bright place, it is difficult to accurately find a distance up to the target object.
On the other hand, as an on-board video camera, a video camera using headlights as fill lights is known in accordance with Jpn. Pat. Appln. KOKAI Publication Nos. 5-189694 and 5-338487, and the like.
Further, a technology as well in which an emission device for emitting infrared radiation as a fill light is added to an on-board video camera, and illumination is carried out while synchronizing an image pickup timing of the video camera and a light emission timing of an infrared fill light from the emission device is well known in accordance with Jpn. Pat. Appln. KOKAI Publication No. 2002-240629 and the like.
Moreover, in Jpn. Pat. Appln. KOKAI Publication No. 2003-134509, a video camera using a laser beam as a fill light is disclosed as an on-board video camera.
In a video camera using infrared radiation or a laser beam as a fill light, it is necessary to add a light source for emitting a fill light, which results in an increase in cost for the apparatus.
Recently, a technology in which two types of range devices such as a stereo camera and a laser radar are provided together, and object recognition carried out in accordance with a predetermined algorithm on the basis of ranged results from both range devices is known in accordance with Jpn. Pat. Appln. KOKAI Publication Nos. 2000-329852 and 2003-121547, and the like.
In the complex type object recognition apparatus in which two types of range devices are provided together, highly reliable ranging performance and object recognition according to a situation are possible by utilizing the advantages possessed by the stereo camera and the laser radar, respectively. Namely, according to the stereo camera, it is impossible to accurately detect a distance up to a target object which is a long way off. However, it is possible to recognize a shape of a target object which is at a comparatively short distance in detail, and it is also possible to sense a road surface and a white line on a road. In contrast thereto, in the laser radar, a shape of a target object cannot be detected in detail, but it is possible to accurately detect a distance up to a target object which is a long way off (for example, a distance greater than or equal to 100 mm).
In above-described Jpn. Pat. Appln. KOKAI Publication Nos. 2000-329852 and 2003-121547, there is disclosed a technology relating to means for optimally integrating both range devices in order to utilize the advantages of the two.